How to report tasks immediately (needed for Boinc 6.12.34 and earlier):

Create, or edit an existing, cc_config.xml file in the Program Data folder for Boinc, using a text editor (Notepad),
- For Vista and Win7 create the file in this folder, C:\ProgramData\BOINC (this folder will likely be hidden, but should open if you type it into Explorer).

Using Multiple GPUs:
Depending on your driver, you may also need to add this line if you want to use multiple GPUs

<use_all_gpus>1</use_all_gpus>

Cache Levels (Additional Work Buffer):
For GPUGRID it is better to set a low cache level of say 0.05days (rather than use the default 0.25days).
Open Boinc in Advanced View, Click Advanced, Preferences, under the network usage Tab set the additional work buffer to a low value.
- This will optimise Work Unit turn around and expedite the project. It will also allow you to collect larger bonuses.

You can tell if it is working if a project disappears as soon as it is 100% done, rather than the project hanging around with the message "ready to report results".

I just got this working in Ubuntu and I had a heck of a time with file ownership and permissions. I'm accustom to other Linux distros but I'm new to Ubuntu so I'm not familiar with how you level up in Ubuntu.

Value 1 on a TONI_HERGunb1 (workunit 1493006, same host as before) is back to the same sort of time as before. I'm about tested out for tonight: maybe tomorrow I'll try it with an empty value string, or even no variable at all, and see if it slows down - maybe just having anything at all there is good enough.

I don’t think that swan_sync works for 6.03 tasks, (compiled for CUDA 2.2). It is there for CUDA 3 or above (the forthcoming 3.1 that might be 11% faster than CUDA 3.0, which is 30-35% slower than CUDA2.2 which does not work for Fermis, so this might even things out).
So it is most notably for Fermi, but note that it requires the cruncher to leave one CPU thread free per GPU, to fully benefit from the Environmental Variable.
If you wanted to use four GPU's a single CPU core is not enough (for all 4 GPUs), you need a Quad core CPU, or better.

I think the variable may work for the more recent 6.72 WU's but to a lesser extent. Either way, it should do soon (if/when these are compiled for CUDA 3.0, or more likely 3.1).
-
Swan_sync now works for the 6.12app and with non-Fermi cards as well as the 6.13app for Fermi cards or some pre-Fermi cards.

All my experiments with SWAN_SYNC in this thread relate to host 71413, which as you can see is an eight-core host (that's eight real cores, not HT semi-cores). I'm running seven BOINC CPU tasks plus one GPUGrid task on the single GTX 470 GPU. Obviously, Windows doesn't exactly run 'one task per core' - the thermal stresses would be horrendous if seven cores were generating maximum heat and the eighth was idle - but there should be plenty of spare cycles for the syncing.

If you look back at the announcement link from last time, you'll see that it is in the "GPUGRID and Fermi" thread. Also, it's clear from that announcement that the 20%-30% speedup I mentioned refers to a single application - by implication, v6.73 - with two modes of operation. That's what I'm failing to see.

I'm not sure where this idea come from, of a physical core ID being specified for the sync process - that goes against everything I've ever learned about multi-tasking operating systems - and it isn't supported by any post I can find from the project developers. But perhaps as you say we should wait for technical clarification.

I'm not sure what the specific cause of it is but DO NOT USE THE SWAN_SYNC WITH PHYS-X DEDICATED TO THE CPU IF YOU ARE RUNNING VISTA 64-BIT. It causes Windows Explorer to continuously stop working and then restarts Explorer over and over in an infinite loop and is extremely difficult to maneuver to change the settings back because you only have about 8 seconds in-between Explorer crashes.

The more recent NVidia drivers are causing many GPUs to reduce their clock rates. So it is a good idea to make sure your cards Power management is set to Prefer Maximum Performance (NVidia control panel, Manage 3D settings, Power management mode).

I recommend that people crunching on Fermi cards control their fan speed using a tool such as EVGA Precision (now available without email registration). Typically these cards will run at up to 91 deg C. At such temperatures the task success rate drops. It is best to keep temperatures under 80deg C and under 70deg C if possible. Doing so will increase task success rates and the cards longevity.

I have added this into my W7 \program data\BOINC folder, but any explanation what it means/does to BOINC in general and GPUGRID specifically? Impact on other gpu projects? Other <coproc> flags documented?

Close Boinc and delete the app_info.xml file. You would have needed to include additional details about the apps to use.

Running multiple tasks on the one GPU is not recommended; it only speeds up running some task types, and these are being phased out.

Content yourself with using the following optimizations:

Creating the swan_sync environmental variable and setting it to zero (0).
Freeing up one CPU core/thread per GPU; use 99% CPU's for one GPU.
Configure the cc_config.xml file to report tasks immediately.
Keep a low Boinc cache.

Increasing the CPU and GPU speeds modestly can increase performance, but avoid overclocking to the point of getting failures as this will reduce overall turnover. Overclocking the GPU a lot can actually increase run times, so make sure your OC is working by comparing completion times of same task types WU's with the same credit. It is usually not worth increasing the voltage, as this will increase power usage, heat, noise and reduce the MTF. Increasing fan speed is always recommended for GPU crunching.

How to stop tasks switching:
Keep a low cache and set set the processor usage to switch between applications every 999sec.
In theory this might affect the running of a long task when a shorter task then downloads, or when you crunch for more than 1 GPU project.

On Vista and Win7 change the NVidia power scheme from adaptive to max performance.

There are four 'processor usage' local Boinc settings that could cause the GPU to suspend and resume frequently. Boinc Manager (Advanced view), Tools, Computing Preferences, Processor Usage tab,
Computing allowed,

While computer is in use (when not ticked)
Use GPU while computer is in use (when not Ticked)
While processor usage is less than (anything other than zero)
Use at most % CPU time (anything other than 100%)

In particular,
- less than 100% CPU time is bad
Also,
- Using TThrottle can cause tasks to stop and start hundreds of times
- if a Kepler GPU with boost gets too hot / loud / expensive: reduce the power target, as this makes the chip run more efficiently
See this and subsequent posts.

SLI is not recommended for GPUGrid.

Only one task can be run on one card, not one task across 3 cards simultaneously (Might change in the future).

While you could run 2 tasks on one card, by configuring an app_info.xml or app_config.xml file, this is generally not recommended; tasks tend to run at >90% GPU Utilization here, so there is no benefit. You could also run out of GDDR memory.

If you experience GPU downclocking open NVidia control panel/Xserver and
change the PowerMizer from "Adaptive" mode to Max Performance if it's available (not always there on XP, but usually is on Vista, Win7 and some Linux systems). Ubuntu 12, 11.04 and 11.10 versions (and others) do not save your performance selection, so you will need to reselect it each time you restart! This often prevents the GPU from down-clocking. If it still downclocks you should try restarting your system, check your temperatures, configure fan controlling software and try reducing your GDDR frequency if need be.

See this Manual Fan Control Guide for setting the fan speed under Gentoo Linux. You can also follow these steps to setup fan control for Ubuntu 11.10 (and similar). Restart to apply the setting.

It is recommended to Not use a screen saver at all. Better to manually turn the monitor off. Behaviour varies from driver to driver with downclocking and crashing common.
See Jacob Klein's post here on the Win7+DVI+295/296 driver issue.

Remember to choose short or long tasks according to your GPU's performance and the amount of time it runs GPUGrid tasks.
You can do this from Your account, GPUGRID preferences
For those crunching Long tasks only, I suggest selecting to accepting normal tasks if no long tasks are available,

If no work for selected applications is available, accept work from other applications? yes

It is not recommended to run multiple GPU projects on the same system. However if you decide to do this it is recommended that you keep a low cache and configure Boinc Manager to "switch between applications every" to a high number (999)minutes. If you have more than one GPU it's better to specify which GPU to use for which project.

Multiple GPU setups.
It is best to use GPU's of similar Compute Capability. Mixing CC1.3 and CC2.0 cards, for example, might result in some errors (mostly for the CC1.3 GPU). Fermi's only differ by being CC2.0 or CC2.1, but even this could be a problem depending on drivers.

Power Settings - If Sleep is enabled computation will stop after the period you set to sleep after. Also note that PCIE and Network power settings in Linux, Vista (especially), W7 and potentially W8 might cause performance/communication issues. I recommend setting these power options to full power (energy ways there is little to be gained from a built in Network card going to sleep).

Adding <use_all_gpus>1</use_all_gpus> to a cc_config.xml file is recommended for systems with more than one usable GPU.
Although the GPUGrid server asks for the tasks to be returned immediately, earlier clients do not respond. So you might want to use <report_tasks_immediately>1</report_tasks_immediately>
Not needed for Boinc versions 7.0.2x onwards.

When installing new drivers, exit Boinc (and close running tasks), install the driver (clean install preferred), and then restart the system.